THE UNIT, the season's Number One new series, topped NBC and ABC combined in viewers and key demos while building on its first-run "NCIS" lead-in, according to preliminary Nielsen affiliate ratings for Tuesday, April 4.

For the night, CBS was second in households (8.7/14), viewers (13.31m), adults 25-54 (4.9/12) and adults 18-49 (3.6/10).

[EDITOR'S NOTE: What follows is the afternoon update with the final national Nielsen ratings.]

"THE UNIT" MARCHES ON

"The Unit" Tops ABC and NBC Combined in Viewers and Key Demos

"The Unit" Builds on its First Run "NCIS" Lead-In

"NCIS" Places a Solid Second in Time Period Against "American Idol"

THE UNIT, the season's Number One new series, topped NBC and ABC combined in viewers and key demos while building on its first-run "NCIS" lead-in, according to Live Plus Same Day National Nielsen ratings for Tuesday, April 4.